Status Report: M48A1 Patton Armor

An E-25 can penetrate its gun mantlet with normal AP (150 penetration) which usually is a big no no area to aim at.
I got curious and went to check the armor model:

The gun mantlet has 114.3 mm of armor and at first glance looks like quite sturdy with that 177.8 mm behind but when you take a better look at it from the inside...

None, zero, nada! A massive hole with nothing but 114.3 mm of gun mantlet. Now, this is normal, the gun has to pass through somewhere, but although this is historically correct wouldn't it be beneficial for a Tier X vehicle to have something less gaped?

Super Pershing

Like that?

No wonder that this tanks are rarely seen in battles, on NA there are only 20k sadomasochists who own it, not even patriotism has convinced them.